/*
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * ListOptions.java
 * Copyright (C) 2006 University of Waikato, Hamilton, New Zealand
 */

package weka.core;

import java.util.Enumeration;
import java.util.Vector;

/**
 * Lists the options of an OptionHandler
 * 
 * @author fracpete (fracpete at waikato dot ac dot nz)
 * @version $Revision: 1.2 $
 */
public class ListOptions implements OptionHandler, RevisionHandler {

	/** the classname */
	protected String m_Classname = ListOptions.class.getName();

	/**
	 * Returns an enumeration describing the available options.
	 * 
	 * @return an enumeration of all the available options.
	 */
	public Enumeration listOptions() {
		Vector result = new Vector();

		result.addElement(new Option("\tThe class to load.", "W", 1,
				"-W <classname>"));

		return result.elements();
	}

	/**
	 * Parses a given list of options.
	 * 
	 * @param options
	 *            the list of options as an array of strings
	 * @throws Exception
	 *             if an option is not supported
	 */
	public void setOptions(String[] options) throws Exception {
		String tmpStr;

		tmpStr = Utils.getOption('W', options);
		if (tmpStr.length() > 0)
			setClassname(tmpStr);
		else
			setClassname(this.getClass().getName());
	}

	/**
	 * Gets the current settings of this object.
	 * 
	 * @return an array of strings suitable for passing to setOptions
	 */
	public String[] getOptions() {
		Vector result;

		result = new Vector();

		result.add("-W");
		result.add(getClassname());

		return (String[]) result.toArray(new String[result.size()]);
	}

	/**
	 * sets the classname of the class to generate the Javadoc for
	 * 
	 * @param value
	 *            the new classname
	 */
	public void setClassname(String value) {
		m_Classname = value;
	}

	/**
	 * returns the current classname
	 * 
	 * @return the current classname
	 */
	public String getClassname() {
		return m_Classname;
	}

	/**
	 * generates a string to print as help on the console
	 * 
	 * @return the generated help
	 */
	public String generateHelp() {
		String result;
		Enumeration enm;
		Option option;

		result = getClass().getName().replaceAll(".*\\.", "") + " Options:\n\n";
		enm = listOptions();
		while (enm.hasMoreElements()) {
			option = (Option) enm.nextElement();
			result += option.synopsis() + "\n" + option.description() + "\n";
		}

		return result;
	}

	/**
	 * generates the options string.
	 * 
	 * @return the options string
	 * @throws Exception
	 *             in case the generation fails
	 */
	public String generate() throws Exception {
		StringBuffer result;
		OptionHandler handler;
		Enumeration enm;
		Option option;

		result = new StringBuffer();

		handler = (OptionHandler) Class.forName(getClassname()).newInstance();

		enm = ((OptionHandler) handler).listOptions();
		while (enm.hasMoreElements()) {
			option = (Option) enm.nextElement();
			result.append(option.synopsis() + '\n');
			result.append(option.description() + "\n");
		}

		return result.toString();
	}

	/**
	 * Returns the revision string.
	 * 
	 * @return the revision
	 */
	public String getRevision() {
		return RevisionUtils.extract("$Revision: 1.2 $");
	}

	/**
	 * runs the javadoc producer with the given commandline options
	 * 
	 * @param options
	 *            the commandline options
	 */
	public static void main(String[] options) {
		ListOptions list = new ListOptions();

		try {
			try {
				if (Utils.getFlag('h', options))
					throw new Exception("Help requested");

				list.setOptions(options);
				Utils.checkForRemainingOptions(options);
			} catch (Exception ex) {
				String result = "\n" + ex.getMessage() + "\n\n"
						+ list.generateHelp();
				throw new Exception(result);
			}

			System.out.println("\n" + list.generate());
		} catch (Exception ex) {
			System.err.println(ex.getMessage());
		}
	}
}
